1. Field of the Invention
The present invention relates generally to systems associated with the drilling, completing and depleting of underwater wells, such as oil, gas or the like, and, more particularly, but not by way of limitation, to systems for forming and installing pipes beneath the surface of a body of water.
2. Brief Description of the Prior Art
It has been the practice for a number of years to use drilling rigs in the Gulf of Mexico and the oceans for the purpose of drilling and completing oil and gas wells and the like. Early offshore rigs were adapted to rest on the floor or bottom of a body of water and drill in a so-called "sit on bottom" position. Thereafter, floating rigs were developed which could drill while floating. While this permitted the drilling of wells in water depths on the order of 1,000 feet or more it left substantial problems such as how to convey fluid products to the surface, for example.
For commercial reasons, when wells are drilled in deeper water, it is desirable to provide an underwater oil or gas collecting station and to convey the oil or gas from a number of wells to such collecting station from whence it is conveyed to a surface collection station.
Moreover, it is not always commercially practical to use divers at such depths because of the limited time that they can remain at such depths, the cost of sophisticated support equipment required, as well as the relatively high salaries of the various personnel involved.
A major problem in perfecting such a deep water collecting system is that of laying and installing the marine pipelines to interconnect the wells with the underwater collection station. Further, various problems are encountered in making the terminal pipeline connections underwater, such as the problems associated with the alignment of the pipelines to be connected, for example. U.S. Pat. No. 3,754,404 discloses a method for interconnecting offshore with other offshore, as well as onshore, installations utilizing a submersible chamber and a series of buoys and wire lines for stringing and pulling the flowline pipe to interconnect such stations.
U.S. Pat. No. 2,548,616 discloses a pipe straightener comprising a plurality of roller motor driven roller elements and a pipe bender comprising a plurality of adjustable roller elements for use in passing a pipe string into a borehole and for use in withdrawing the pipe string from the borehole.
U.S. Pat. No. 3,595,312 disclosed a method and apparatus for installing offshore pipelines wherein the pipe was moved through a curved tube or J-tube shaped to change the direction of the pipe from vertical to horizontal, the pipe exiting the J-tube extending along the floor of a body of water. In one form, rollers were included in the J-tube for reducing friction.